In a new interview with People magazine, Cindy McCain revealed her secret struggle with migraines. She compared the condition to her husband's torture as a prisoner of war in Vietnam.

She says one of her first challenges was finding the words to describe how painful the headaches can be. When she first told her husband, a former POW during the Vietnam War, she used a word she knew he would understand.

"Torture," she says. "Being tied to a chair for four days. I can't imagine how unbearable that pain must have been, but yeah, I can, because a migraine may come close."

In this 1968 footage from a French documentary, an imprisoned John McCain discusses his ordeal in Vietnam.